Advanced Water Purification

Padre Dam's Advanced Water Purification Project is a potential new source of water that would be locally controlled, reliable, drought-proof and environmentally sound.
Too Valuable to Use Once
Padre Dam Municipal Water District imports 100 percent of its drinking water supply from hundreds of miles away, from the Sacramento Bay Delta and the Colorado River. Our economy, livelihood and well-being depend on having a reliable source of water.  

Ever-increasing technology has brought progress and innovation in the areas of water conservation, seawater desalination and water recycling. Recent drought and imported water supply challenges have highlighted the need for Padre Dam to explore new possible water sources to ensure a safe, reliable water supply and to safeguard the vitality of East County’s economy and quality of life.

4 step AWT processA New Source of Water 

Padre Dam has identified an exciting water recycling opportunity that would diversify our water supply and reduce dependency on imported water. If the project moves forward, it would provide up to 2,000 to 3,000 acre feet per year of drinking water to Padre Dam customers. This is approximately 15 percent of Padre Dam’s current drinking water demands. 

The Advanced Water Purification Demonstration Project, funded through a $3 million state grant, will include the planning, design, installation and operation of a demonstration plant using Advanced Water Treatment (AWT) technologies that meet or exceed the California Public Health Department’s draft regulations. The water produced during this phase is for testing purposes only and will not be utilized in the drinking water system.

The Project is inspired by the natural water cycle, and would be a new source of water that is locally controlled, reliable, drought-proof and environmentally sound. 

In addition to the Demonstration Project, Padre Dam continues to study the Santee Basin Aquifer to determine its feasibility and capacity for the Advanced Water Purification Project. Electrical Resistivity field testing was completed in March 2013 providing initial data on the depth and breadth of the aquifer. In March 2014, test wells were drilled to provide additional data on the aquifer. 

The Advanced Water Purification Demonstration Project is being funded by a state grant and will not impact water rates.

Rigorous Purification Process
The purification process begins with treating recycled water using state-of-the-art technologies. This treatment process includes four advanced water treatment steps - free chlorine disinfection, membrane filtration, reverse osmosis and ultra violet/advanced oxidation. After treatment, it would be injected into the groundwater basin where it is naturally filtered and would then be withdrawn and treated again prior to distribution as drinking water. 

During the Demonstration Project, the purified water will be tested daily to ensure it meets the public health objectives for California Public Health Department approval. The ultimate goal is to develop a proven full-scale project that utilizes water produced within the District to serve Padre Dam Municipal Water District’s customers. 

Project Schedule and Funding

The Advanced Water Purification Demonstration Project is expected to last approximately three years. Work on the project began in fall of 2013 and will be complete in summer of 2016. This timeline includes a full year of facility operation. At that time, the Demonstration Project will produce approximately 100,000 gallons of AWT water per day for demonstration and testing purposes.

Funding for the Advanced Water Purification Demonstration Project is being provided through a $3 million grant that has been secured through the California Department of Water Resources Proposition 50 Grant through San Diego’s Integrated Regional Water Management Group.

A Regional Water Solution

An additional study is being conducted to consider the potential for expanding the Santee Advanced Water Purification Program to include more East County communities. This proposed expanded project would include the service areas of Padre Dam Municipal Water District, Helix Water District, a portion of the County of San Diego, and the City of El Cajon. This study will evaluate expanding Padre Dam’s Advanced Water Treatment facility, and advanced treatment systems, in order to provide a new water supply for additional local users beyond Padre Dam’s water customers.